Newly unsealed court documents show that, in the months before the massacre, shooter Stephen Paddock took measures to muddy the waters in the law enforcement investigation he knew would follow his attack. FBI search warrants state that Paddock “destroyed or tried to hide digital media devices” that he assumed the feds would be after, according to a New York Times report. In fact, Paddock took a number of steps aimed at tripping up investigators, and the FBI team trying to get to the bottom of the shooting wrote that the 64-year-old exhibited “a level of sophistication which is commonly found in mass casualty events.”

Although the bureau still has not determined a motive for his attack, they’ve slowly traced the winding trail that led him to the Mandalay Bay hotel room last October. They said he used multiple communication devices, including a prepaid cellphone. Three phones were found in the room where Paddock died, two of which investigators were able to search, but one that they could not unlock, authorities said. An agent wrote in the search warrants that “if there were any information related to a potential conspiracy, it would be found within” the locked phone, which operated on the Google platform.

In the warrants, agents pushed for access to Danley’s email account, saying that “[it could] lead investigators to determine the full scope of Stephen Paddock’s plan and Marilou Danley’s possible involvement.”

A number of the devices that Paddock used in the shooting were ordered online, including a holographic weapon sight, authorities said.

Authorities have been able to gain access to Paddock’s email accounts and say that he emailed between two accounts referring to items that he used in the attack, including the bump stock that he attached to his weapon. Although they’re not sure, investigators said there’s a possibility that somebody else was handling one of the email accounts, and they believe that identifying the person could help pull back the veil that surrounds Paddock’s motives.